Walking in an unstable Masai Barefoot Technology (MBT) shoe introduces kinematic and kinetic changes at the hip, knee and ankle before and after a 6-week accommodation period: a comprehensive analysis using principal component analysis (PCA)

Abstract

Background: Scientific and anecdotal evidence suggests that some individuals who wear the unstable Masai Barefoot Technology (MBT) shoe experience a reduction in back and joint pain. A more comprehensive biomechanical gait analysis is needed to better understand the mechanisms for symptom relief and what the long-term implications of wearing these shoes might be on the body. Objective: The aim of this study was to determine the gait changes introduced at the hip, knee and ankle before and after wearing an unstable MBT shoe for a 6-week accommodation period. Methods: Three-dimensional joint angles and moments were measured for 23 healthy individuals while walking in an unstable MBT shoe and a stable control shoe, both before and after a 6-week accommodation period of wearing the unstable shoe at their workplace. Principal component analysis (PCA) was used on the stance phase waveforms to identify differences between the two shoes and two testing sessions. Results: Joint angle and moment differences between the two shoe conditions were identified both before and after wearing the unstable shoe for the accommodation period. Notable kinematic changes included reduced hip flexion–extension and ankle adduction–abduction range of motion, increased early stance dorsiflexion and increased knee internal rotation for unstable shoe walking. Ankle moments tended to be greater for the unstable shoe and at the hip and knee, both increases and decreases in moments were observed. Conclusions: While many of the identified changes agree with previous research, this is the first study to report increases in some joint moments for the unstable MBT shoe. These increases along with other notable changes do, however, require further investigation to better understand the long-term implications of the unstable MBT shoe.